I spent most of last weekend investigating displacement maps and refactoring my terrain code so I would be ready to support DirectX 9 displacement maps, only to discover that my Ti 4600 doesn't support it. D'oh. I guess part of me wasn't listening to the voice of reason.. after all, my card doesn't support anything past vertex/pixel shader 1.1.
I'm bummed about replacing this card because it truely is a fast card. It runs every new game I've tried on it just fine; or at least at a high enough level that it doesn't distract me. I'm bummed because in order to get a card that is superior to it in speed I have to spend at least $110. In the past when I've replaced my video card getting a faster model only meant $50 because technology had been moving so fast. I guess not now.
In today's graphics market it looks like the chip makers are going after features and pipelines over speed. The new cards feature more pipelines, faster memory, etc., but the raw texel fill rates aren't dramatically higher than what was available a year ago.
So my new card is going to be an nVidia 6600 GT, it looks like right now that's the best bang for the buck. I opted to get one of the MSI models, since everyone seems to be saying they're nice and quiet and don't run too hot.